If you can't convince your mother that they are harmless, I would respect her opinion and quit if she asks you too. If it doesn't bother her, than woot for you!
Excuse me, are you f***ing kidding me? You're telling him that if he can't explain LDing to his close-minded superstitious misled mother, he should give up something that can give him once-in-a-lifetime experiences ON COMMAND? There is such a thing as a wrong opinion. If for some reason you don't get that, how about the way people in South USA used to feel about slavery? How can someone's opinion stop you from recognizing dreams? Seriously. It shouldn't be a lucky thing that his mother doesn't mind LD.